Worklet: Enable Firewall on macOS

Originally introduced in Mac OS X Leopard (10.5.1), the built-in macOS Firewall limits incoming connections on a per-application basis (as opposed to a per-port basis). Disabled by default, this worklet enables the macOS firewall.

Evaluation:

#!/bin/bash

# helper function to check if a command exists
function command_exists {
    type "$1" &> /dev/null
}

# only evaluate if the socketfilterfw command is available
if command_exists /usr/libexec/ApplicationFirewall/socketfilterfw; then
    # check if the firewall is enabled
    /usr/libexec/ApplicationFirewall/socketfilterfw  --getglobalstate | grep -q 'enabled'

    # yes? no?
    exit $?
fi

# socketfilterfw command is not available, move along
exit 0

Remediation:

#!/bin/bash

# turn the firewall on
/usr/libexec/ApplicationFirewall/socketfilterfw --setglobalstate on

# how did we do?
exit $?